Delete socket adapters

Boost beast, ASIO, and networking TS already have mechanisms for
injecting unit tests, using template parameters.  We already use this to
some extent, although we pass through socket_adapters.  Now that we have
constexpr if, we have the ability to simplify this code quite a bit.

Tested by:
Pulled down phosphor-webui, ran redfish service validator.  Observed no
errors.

Change-Id: Ib8734aeb4c9139b56705060f6196e8ae16458fe9
Signed-off-by: Ed Tanous <ed.tanous@intel.com>
diff --git a/CMakeLists.txt.in b/CMakeLists.txt.in
index edba792..0aed5d5 100644
--- a/CMakeLists.txt.in
+++ b/CMakeLists.txt.in
@@ -36,8 +36,8 @@
 
 externalproject_add (
     Boost URL
-    https://dl.bintray.com/boostorg/release/1.66.0/source/boost_1_66_0.tar.gz
-    URL_MD5 d275cd85b00022313c171f602db59fc5 SOURCE_DIR
+    https://dl.bintray.com/boostorg/release/1.68.0/source/boost_1_68_0.tar.gz
+    URL_MD5 5d8b4503582fffa9eefdb9045359c239 SOURCE_DIR
     "${CMAKE_BINARY_DIR}/boost-src" BINARY_DIR "${CMAKE_BINARY_DIR}/boost-build"
     CONFIGURE_COMMAND "" BUILD_COMMAND "" INSTALL_COMMAND mkdir -p
     "${CMAKE_BINARY_DIR}/prefix/include/" && cp -R